1. Field of the Invention
The present invention relates to a digital image processing device and more particularly to the digital image processing device to feed image data to an image display device.
The present application claims priority of Japanese Patent Application No. 2003-090064 filed on Mar. 28, 2003, which is hereby incorporated by reference.
2. Description of the Related Art
Resolutions being employed in a digital image processing device includes, for example, in the case of a color-display plasma display panel, many levels of resolutions mainly such as WVGA (Wide-Video Graphics Array) providing 2559 pixels×480 lines, HD (High-Definition) providing 3072 pixels×768 lines, and WXGA (Wide-Extended Graphics Array) providing 4095 pixels×768 lines and such the resolutions tend to increase in level. To supply a display panel at a low cost, a method is employed in which, by achieving commonality of specifications of components including a comparatively high-cost driving circuit (that is, a data driver, thereafter being simply called a “driver”) or a like, a digital image processing device can be applied to various display panels.
FIGS. 5A, 5B, and 5C are diagrams showing examples of methods for connecting various display panels to drivers in which examples of arrangement of the drivers 501 each being made up of, for example, 96 pixels and being able to operate all image lines included in various display panels. If the driver 501 is commonly used for connecting display panels with different resolutions, that is, the display panel 502 with WXGA resolutions, display panel 503 with HD resolutions, and display panel 504 with WVGA resolutions, in the case of the display panel 503 with HD resolutions, as shown in FIG. 5B, resolutions in a horizontal direction can be realized by fully using the driver 501 having 96 pixels. However, in the display panel 502 with WXGA resolutions and the display panel 504 with WVGA resolutions, as shown in FIG. 5A and FIG. 5C, unused pixels are left.
Moreover, the driver 501 is so constructed ordinarily that, in order to reduce the number of input terminals, after image data has been captured from 2 to 4 pieces of input terminals in a time-series manner, 96 pixels are output in parallel (for example, uPD16341/A, 96-bit AC-PDP driver, Material number S14076JJ5V0PM00 (Fifth edition), June 1999).
Therefore, for example, in the case of the display panel 502 with WXGA resolutions and the display panel 504 with WVGA resolutions, it is necessary that data (hereafter, being referred as a “redundant pixel” or “dummy data”) corresponding to portions being not connected between the display panel 502 or the display panel 504 and the driver 501 has to be embedded in an image line to be transferred to the driver 501. Due to this, there are some cases in which a length of an image line to be transferred to a driver is longer than that to be actually displayed on a display panel. Moreover, a position in which dummy data is embedded and the number of pixels are varied depending on types of drivers. In recent years, 192-bit and 256-bit drivers, besides 96-bit driver, are commercially available.
FIG. 6 is a block diagram showing an example of configurations of a conventional digital image processing device. In a video input signal 601, after the video input signal 601 has been processed by a signal processing section 602, is embedded dummy data which corresponds to resolutions of a display panel to be used, by a redundant pixel embedding section 603. The image line in which dummy data is embedded, after having been stored in a frame memory 604, is transferred to each of drivers 605 in a time-series manner and is then displayed in a display panel 606 (with WXGA resolutions).
In a conventional image processing device, in order to transfer an image line containing dummy data which corresponds to a resolution of a display panel to a driver, in the case of, for example, a display panel with WXGA resolutions, as shown in FIG. 6, dummy data has been, in advance, embedded by the redundant pixel embedding section 603 in an output image line each having 4095 pixels in the signal processing section 602 so that the number of pixels becomes 4224 and the data having 4224 pixels is stored in the frame memory 604. Thus, by having the redundant pixel embedding section 603 embed dummy data corresponding to a resolution of a display panel, the digital image processing device can be applied to a display panel with a different resolution.
Moreover, so far as a research on prior art performed within a range of ordinary efforts is concerned, no information about references concretely describing contents of the above described conventional technology is obtained.
However, the conventional digital image processing device has problems. That is, a first problem associated with the conventional digital image processing device is an increase in a capacity of a frame memory. This occurs because a redundant image line having embedded dummy data which is not actually displayed is stored into a frame memory, that is, for example, if a display panel with WXGA resolutions uses a 96-bit driver, capacity being equivalent to about 3% of a total capacity of the frame memory is used for dummy data which is not displayed.
A second problem associated with the conventional digital image processing is an increase in an amount of hardware. This occurs because both a function of embedding dummy data in an image line and a function of transferring data to a driver of a display panel in a time-series manner have to be individually designed.